release/src/router/apcupsd/src/lib/apcevents.c

   1 /*
   2  * apcevents.c
   3  *
   4  * Output EVENTS information.
   5  */
   6
   7 /*
   8  * Copyright (C) 1999-2006 Kern Sibbald
   9  *
  10  * This program is free software; you can redistribute it and/or
  11  * modify it under the terms of version 2 of the GNU General
  12  * Public License as published by the Free Software Foundation.
  13  *
  14  * This program is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  17  * General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU General Public
  20  * License along with this program; if not, write to the Free
  21  * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
  22  * MA 02111-1307, USA.
  23  */
  24
  25 #include "apc.h"
  26
  27 #define NLE   50                   /* number of events to send and keep */
  28
  29 /*
  30  * If the ups->eventfile exceeds ups->eventfilemax kilobytes, trim it to
  31  * slightly less than that maximum, preserving lines at end of the file.
  32  *
  33  * Returns:
  34  *
  35  * -1 if any error occurred
  36  *  0 if file did not need to be trimmed
  37  *  1 if file was trimmed
  38  */
  39 int trim_eventfile(UPSINFO *ups)
  40 {
  41    int nbytes, maxb, i, rwerror = 0, status = -1;
  42    struct stat statbuf;
  43    unsigned char *buf;
  44
  45    if (ups->eventfilemax == 0 || ups->event_fd < 0 || ups->eventfile[0] == 0)
  46       return 0;
  47
  48    maxb = ups->eventfilemax * 1024;
  49    if (stat(ups->eventfile, &statbuf) < 0)
  50       return -1;
  51    if (statbuf.st_size <= maxb)
  52       return 0;                    /* file is not yet too large - nothing to do */
  53
  54    maxb = (maxb * 80) / 100;       /* file is too large - reduce to 80% of max */
  55    buf = (unsigned char *)malloc(maxb);
  56    if (!buf)
  57       return -1;
  58
  59    write_lock(ups);
  60
  61    /* Read the desired number of bytes from end of file */
  62    if (lseek(ups->event_fd, -maxb, SEEK_END) < 0) {
  63       log_event(ups, LOG_CRIT, "lseek failed in trim_eventfile.");
  64       goto trim_done;
  65    }
  66
  67    nbytes = 0;
  68    while (nbytes < maxb) {
  69       int r = read(ups->event_fd, buf + nbytes, maxb - nbytes);
  70
  71       if (r < 0)
  72          rwerror++;
  73       if (r <= 0)
  74          break;
  75       nbytes += r;
  76    }
  77
  78    /* Skip to the first new line */
  79    for (i = 0; i < nbytes; i++) {
  80       if (buf[i] == '\n') {
  81          i++;
  82          break;
  83       }
  84    }
  85    nbytes -= i;
  86
  87    /* Truncate the file and write the buffer */
  88    lseek(ups->event_fd, 0, SEEK_SET);
  89    ftruncate(ups->event_fd, 0);
  90    while (nbytes) {
  91       int r = write(ups->event_fd, buf + i, nbytes);
  92
  93       if (r <= 0) {
  94          rwerror++;
  95          break;
  96       }
  97       i += r;
  98       nbytes -= r;
  99    }
 100    status = 1;
 101
 102 trim_done:
 103    write_unlock(ups);
 104    free(buf);
 105
 106    if (rwerror)
 107       log_event(ups, LOG_CRIT, "read/write failed in trim_eventfile.");
 108
 109    return status;
 110 }
 111
 112 #ifdef HAVE_NISSERVER
 113
 114 /*
 115  * Send the last events.
 116  * Returns:
 117  *          -1 error or EOF
 118  *           0 OK
 119  */
 120 int output_events(int sockfd, FILE *events_file)
 121 {
 122    char *le[NLE];
 123    int i, j;
 124    int nrec = 0;
 125    int stat = 0;
 126
 127    for (i = 0; i < NLE; i++)
 128       le[i] = NULL;
 129
 130    for (i = 0; i < NLE; i++)
 131       if ((le[i] = (char *)malloc(MAXSTRING)) == NULL)
 132          goto bailout;
 133
 134    i = 0;
 135    while (fgets(le[i], MAXSTRING, events_file) != NULL) {
 136       nrec++;
 137       i++;
 138       if (i >= NLE)                /* wrap */
 139          i = 0;
 140    }
 141
 142    if (nrec > NLE) {
 143       nrec = NLE;                  /* number of records to output */
 144       i -= (i / NLE) * NLE;        /* first record to output */
 145    } else {
 146       i = 0;
 147    }
 148
 149    for (j = 0; j < nrec; j++) {
 150       if (net_send(sockfd, le[i], strlen(le[i])) <= 0)
 151          goto bailout;
 152
 153       if (++i >= NLE)
 154          i = 0;
 155    }
 156
 157    goto goodout;
 158
 159 bailout:
 160    stat = -1;
 161
 162 goodout:
 163    if (net_send(sockfd, NULL, 0) < 0)   /* send eof */
 164       stat = -1;
 165
 166    for (i = 0; i < NLE; i++)
 167       if (le[i] != NULL)
 168          free(le[i]);
 169
 170    return stat;
 171 }
 172
 173 #endif                             /* HAVE_NISSERVER */